Serial number embossing apparatus

ABSTRACT

A power press is equipped with a progressive die for continuously working strip stock into perforated plates having embossed inscriptions and serial numbers, such as automobile license plates. The die includes a flat concentric assembly of relatively rotatable rings each of which has a circular series of consecutive digit embossing elements at the obverse side of the assembly. At the converse side of the ring assembly a back and forth swingable indexing arm cooperates with notches in the rings so as to rotate the rings stepwise in predetermined order and present the digit embossing elements thereof in successive serial number configurations.

United States Patent. 19

Alexander July 23, 1974 SERIAL NUMBER EMBOSSING APPARATUS PrimaryExaminer-Clyde l. Coughenour [76] Inventor: Donald Ray Alexander,Treasure Attorney Agent or Flrm'james Nlues Hills Addition, RR. 3, Box291, Conway, Ark. ABSTRACT [22] Filed: Oct 11, 1972 A power press isequipped with a progressive die for continuously working strip stockinto perforated plates PP 296,602 having embossed inscriptions andserial numbers, such as automobile license plates. The die includes aflat [52] us. 01. 101/19 101/7 B f assembly of relatively mtatabl?rings. each 51 1m. (:1 B44b 5/00, B 111 47/50 whwh has a Seriescfmsewtve [58] Field of Search 101/18, 19, 29, 7s, bossing elements 9the slde Of the assembly- 7' 83 At the converse side of the rlngassembly a back and forth swingable indexing arm cooperates with notches[56] References Cited in the rings :0 as tc:i rotate the l:ingjsstepwise in predetermlne or er 'an resent t e 1 1t em ossmg e e- UNITEDSTATES PATENTS ments thereof in suc essive serial umber configura-680,646 8/1901 Cooley 101 19x tiom 1,407,769' 2/1922 Premo 101/181,423,236 7/1922 McCombs l0l/l9 8 Claims, 33 Drawing FiguresPATENTEDJUL23I974 arm 01 or 15 PAIENTEIJ JUL23l974 saw 03 av 15;

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m1 01am;

Y 34 Z HEIFIF Z i/A- O Y 2 i i K 0 FIG. 14

mal 3.924.921 mama] mm as a 15.

FIG. 18

FIG. 19

FIG. 20

PATENTEU M sun :mor 15 msmanmwn sum 13m 15 changed, by hand, and inorder to do this the plates from one press to the next.

1 SERIAL NUMBER EMBOSSING APPARATUS BACKGROUND OF THE INVENTION cessiveplates with consecutive serial. numbers; anda rimming press forembossing the plates with the name of the state, the month and year ofissue and usually the strip stock to length and punching mounting holesinto the blanks; a numbering press for embossingsucsome promotinglege'nd. The performance of the men- .tioned manufacturing operations bymeans of separate presses has obvious disadvantages. The'presses notonly involve a"substahtial capital investment but'for-high volumeproduction operating personnelmustalso -be provided for each press. Thenumberingpresses as heretofo'reemployed haveusually beenof the typewherein the digits; of the serial number had to be more than oneoperator was required.

Further, the numbering presses as heretofore employed have usually beenunable to turn out thesame number of plates 'perminute asthe blanking,punching and rimming presses. For that reason more than one numberingpress has usually been provided to match the production capacity'of theother presses. When this was done'it meant not'o'nly an increase of thecapital investment but also an increase of the number of opera tors forthe entire product line. Also, the use of individual presses for thevarious manufacturing operations entailed the need for a relativelylarge crew'to transport sUMMARY'o THE INVENTION r e Generally, it is anobject of the invention to overfacture of serially numbered automobilelicense plates. {LAnotherobject of .the invention is to provide an im-'.proved power press for continuously working strip stock into seriallynumbered plate members.

A further objectof the invention is to "provide a power'press of theabove mentioned character incorporating an improved serial numberembossing mechanism which automatically advances, the serial numberafter each embossing stroke of the press.

A further object of the invention is to provide a elements thereon andare rotated step by step in'predetermined order by an 'arcuately backand forth swingefficiently i come the hereinabove outlined disadvantagesand I shortcomingsof the prior art with respect to the manuis to providea ferent operating condition.

able indexing arm so as to present said digit embossing BRIEFDESCRIPTION OF THE DRAWINGS The foregoing and other objects andadvantages of the invention will become morefully apparent from thefollowing description of a preferred embodiment of the inventionillustrated by the accompanying drawings, wherein:

FIG. 1- is a perspective view of a power press embodying the invention;

FIG. 2 is a partial sectional press shown in FIG. 1;

FIGQ3 is a plan view of a progressive die incorporated in\the powerpress shown in FIG. 1; I

FIG. 4 is a worms eye view of a progressive counter die incorporated inthe power press shown in FIG.;1;

FIG. 5 is'a perspective view of an embossing die detail;'

' FIG.6 is a view of the obverse side of a concentric decimal ringassembly; 7 I

FIG. 7 is a view of the converse side of the decimal ring assembly shownin FIG. 6;

FIG. 8 is'a plan view of an embossing ring support and associated partsincorporated in the power press elevation of the power shown in FIG. 1;

FIG. 9 is a section on line 9-9 of FIG. 8;

FIG. 10 is an exploded perspective view of a ries shown assembled inFIG. 9;

FIG. 11 is a section on line 11--ll of FIG. 9;

FIG. 12 is a section similar to FIG. 11 with parts shown in a differentposition of adjustment;

FIG. 13 is a section on line 13-13 of FIG. 8; FIG. 14 is a fractionalsection on line 14? of FIG.

FIG. 15 is a section on line 15-15 of FIG. 6;

FIG. 16 is a section on line 16--16 of FIG. 6

FIG. 17 is an exploded'perspective view of parts shown in FIG. 16; I V AFIG. 18 is a sectional view along line 18-18 in FIG. 3, showing anindexing mechanism in a first operating condition; I f l.

FIGS. 19 and 20 areviews similar to FIG. 18-, showing the indexingmechanism in successive conditions of adjustment; I T

FIGS. 21-30 are schematic views of the decimal ring assembly andindexing mechanism in successive conditions of adjustment; FIG. 31 isa'schematic illustration of successive manufacturing operations of thepower press shown in FIG.

pawl se- FIG. 32 is an electro-pneumatic circuit diagram; and

FIG. 33 shows thecircuit diagram of FIG. 32, in a dif- DETAILEDDESCRIPTION The power press shown in' FIG. 1 generally comprises 3 Iscription embossing section 9; a double length idle section 11 (FIG. 2);and a blanking section 12.

The upper platen 3 (FIG. 4) mounts a progressive counter die comprisinga punch section 13; an elastically deformable pad section 14; a rimmingsection 16; a double length idle section 17; and a blanking section 18.A shown in FIG. 5, a flat, rectangular pad of elastically deformablematerial, such as Urethane, is seated in a rectangular recess of amounting plate 20 which in turn is secured to the under side of theupper platen 3. The stationary perforating section 7 and the oppositeperforating section 13 cooperate during ,a downward stroke of the ram 4to punch three round holes 19 and one key hole 21 into strip stock 22 asshown in FIG. 28. An intermittent feed mechanism (FIG- 1) for advancingthe strip stock 22.step by step from a supply reel 23 into the workingspace between the stationary and movable platens 2 and 3 is ofconventional construction and comprises gripper and retainer assemblies24, 26 and a pneumatic feed cylinder 27. An expanding stroke of the feedcylinder 27 advances the strip stock a distance equalto the length ofthe finished license plate.

Succeeding the punch section 7 on the stationary platen is the serialnumber embossing section 8 which is constructed as follows. As shown inFIG. 1 and FIG. 8, a generally circularplate 25 is mounted on the lowerplaten 2 in a horizontal position, and at its upper side the plate 25mounts an anvil block 28,}and two radial support bars 29 and 31. On topof the anvil block 28 and radial support bars rests a flat concentricassembly of five relatively rotatable decimal rings U, W, X, Y and Z. Acircular series of anti-friction balls 32 (FIG. is seated in a circularrace at the inner periphery of the decimal ring U and in a complementaryrace at the outer periphery of the decimal ring W. Another series ofanti-friction balls 33 is similarly seated between the decimal rings Wand X; and a third series of antifriction balls 34 is similarly seatedbetween the decimal rings Y and Z. As further shown in FIG. 8, the anvilblock 28 has a radially outer abutment 36 presenting an arcuatelyconcave guide face 37 for cooperative engagement with the outerperipheryof the decimal ring U. Another abutment 38,at the radially inner end ofthe anvil blockv 28 presents an arcuately convex guide face 39 forcooperative engagement with the inner periphery of the decimal ring Z.At its upper side the abutment 38 has a raised embossing code letterwhich may be any letter of the alphabet and which has here been selectedasthe letter A. Intermediate the abutments 36 and 38 the anvil block 28has an arcuate abutment 41 presenting a convex guide face 42 forcooperative engagement with the-inner periphery of the decimal ring X,and a concave guide face 43 for the outer periphery of the decimal ringY. At its upper side the abutment 41 has a rectangular projection 40 forembossing the license plate with a divider mark between the third andfourth digit of the. serial number- A radially outer guide'lug 44 (FIG.8) and a radially inner pressure roller 46 are carried by each of theradial support bars 29 and 31, the guide lugs 44 engaging the outerperiphery of the first decimal ring U, and the M rollers 46 bearing downupon the last decimal ring Z.

, At the obverse side of the decimal ring assembly each of the decimalrings U, W, X, Y and Z is provided with a circular series of tenconsecutive digit embossing elements numbered zero to nine at equalangular spacings. At the converse side of the decimal ring assembly, theserial number embossing section of the lower die is provided with anindexing mechanism which is operable to rotate the decimal rings step bystep in predetermined order so as to present the digit embossingelements of the decimal rings in successive serial number configurationover the anvil bar 28.

As shown in FIG. 7 and FIG. 15, the first decimal ring U has acircularseries of ten equally spaced indexing notches U to U,, at itsunder side adjacent the outer periphery of the ring U, and at its innerperiphery, directly opposite to the indexing notch U the ring U 'has anauxiliary notch Ua.

The second decimal ring W, as well as the third decimal ring X, and thefourth decimal ring Y are each provided at their under-sides andadjacent their outer peripheries with a circular series of ten equallyspaced indexing notches, and with one auxiliary notch adjacent theirinner peripheries. The indexing notches of the second decimal ring arenumbered W W those of the third decimal ring are numbered X -X and thoseof the fourth decimal ring are numbered Y Y Auxiliary notches W X,,, andY are provided at the under sides and adjacent the inner peripheries ofthe rings W, X and Y directly opposite to the indexing notches W X and Yrespectively. The fifth, that is the radially innermost, decimal ring Zhas a circular series of ten equally spaced indexing notches Z Z at itsunderside and adjacent its outer periphery.

All the indexing and auxiliary notches of all the decimal rings areprofiled alike as shown in FIG. 16. A hardened steel block 45 is securedin each notch by a screw 50, as shown in FIG. 17. Removal of the block45 from the notch Ua and from the notches 'W W permits insertion of theballs 32 between the decimal rings U and W. The balls 33 may besimilarly inserted between the rings W and X, and the balls 34 may beinserted in the same manner between the rings Y and Z.

In the condition of the serial number embossing section as shown inFIGS. 3 and 6, the ciphers of all five decimal rings are presented inzero serial number configuration over the anvil bar 28 in line with thecode letter A. Rotary adjustment of the decimal rings to the zero serialnumber configuration as shown in FIG. 3 also brings the indexing notchesU W X Y and Z and the auxiliary notches U W X and Z into radialalignment as shown in FIG. 21.

Selective rotation of the decimal rings in predetermined order so as topresent the embossing digits of the five rings in successive serialnumber configurations is effected by means of a back and forth swingableindexing arm generally designated in FIG. 8 by the reference numeral 64.The arm comprises a solid bar 47 which extends radiallyfrom the centerof the decimal ring assembly and is swingable horizontally back andforth below the ring assembly on a pivot pin 48 carried on the plate 25.The bar 47 extends radially outward somewhat beyond the outermostdecimal ring U (FIG. 3) and it is supported at its outer end by a roller49 riding on the plate 25. t

A pneumatic double acting cylinder 51 is universally swiveled at itsbarrel end on a bracket 52 secured to the plate 25. The piston rod 53 ofthe cylinder has a universal swivel connection with an actuating lever54 (FIG.

. 1 18) of the indexing arm 64, the lever 54 extending upwardly from thelower side of the ring assembly through the space between rings X and Y.Air hoses 56 and 57 (FIG. 1) lead from the barrel end and from the glandend, respectively, of thecylinder 51 to a solenoid valve 58 on the mainframe 1. A hose line 59 connects the solenoid valve 58 with a source ofair pressure 61, and the solenoid valve has an exhaust pipe 62 for theemission of air therefrom. Up and down movement of the ram 4 actuateselectrical control switch SW4, Sw-2 and TS (FIG. 32) for the solenoidvalve so as to direct air pressure alternately to the barrel end and thegland end of the cylinder 51. Admission of air pressure to the barrelend of the cylinder 51 causes swinging of the indexing arm 64 from theindexing position in which it is shown in FIGS. 3 and 8, to a catchposition indicated by the dash-dotted line 62 in FIG. 8, and admissionof air pressure to the gland end of thecylinder 51 causes swinging ofthe indexing arm 64 from the catch position back to the indexingposition shown in FIG. 3 and FIG. 8.

Referring to FIGS. 9-12 and 18, the'bar 47 of the indexingarm 64 has anelongated recess 63 (FIG. 9) which is closed at one side by a fixed wallmember 64 and which is faced at the other side by a swingable fence bar66. A hinge 67 (FIG. 11) connects the fence bar 66 to the lower part ofthe bar 47, and a pair of shoulder bolts, one of which isshown at 68 inFIG. 11 and FIG. 12, limit swinging of the fence bar 66 away from bar47. The actuating lever 54 is secured to the fence bar 66by bolts 69. Atthe upper side of the bar 47 the recess 63 is spanned by a spring steelleaf 71 which is secured to the fence bar 66 by two screws 72, one, asshown in FIG. 8 and FIG. 11, at the radially outer end of the fence bar,and the other, as shown in FIG. 8, at the radially inner end of thefence bar. Theleaf 71 furtherhas asliding connection at its oppositeends with the bar47, the radially outer sliding connection, as shown inFIGS. 9, 11 and 12 comprising a screw 73 and a slotted hole 74 in theleaf 71, this connection being duplicated at the radially inner end ofthe leaf 71 as shown in FIGS. 8 and 9.

FIG. 10 shows an exploded view of five pawls 76, 77, 78, 79 and 81 whichin theassembled condition of the indexing arms aremounted within therecessed portion 63 ofthe bar 47. Each pawl has a hinge lug 82 by meansof which is mounted on 'a long hinge pin 83 extending across the recess63 of the bar 47. Each pawl is further biased upwardly against theunderside of the decimal ring assembly U, W, X, Y, Z by a coil spring 84reacting between the bar' 47 and the respective pawl.

The pawl 76 underlies the decimal ring U (FIG. 9) and has a roller 86 incooperable relation to the indexing notches Uu-Ug of the decimal ring U.

The pawl 77 bridges the decimal rings U and W (FIG. 9) and has a roller87 in cooperable relation to the auxiliary notch Ua of the ring U, andanother roller 88 in cooperable relation with the indexing notches W -Wof the decimal ring W.

The pawl 78 bridges the decimal rings W and X (FIG. 9) and has a roller89in cooperable relation with the auxiliary notch W, of the ring W andanother roller 91 in cooperable relation to the indexing notches X -X,of the decimal ring X.

The pawl 79 bridges the decimal rings X and Y (FIG. 9) and has a roller92 in cooperable relation with the auxiliarynotch X, of the ring X, andanother roller 93 in cooperative relation with the indexing notchesYq-Yg of the ring Y.

The'pawl 81 bridges the decimal rings Y and Z (FIG. 9) and has a roller94 in cooperative relation with the auxiliary notch Y, of the ring Y,and another roller 96 in cooperative relation to the indexing notches 2-2 of the ring Z.

As further shown in FIGS. 9 and 10, the pawl 77 has an upper couplinglug 97 at its side adjacent the pawl 78, and the pawl 78 has a lowercoupling lug 98 at its side adjacent the pawl 77. Similarly, the pawl 78has an upper coupling lug 99 at its side adjacent the pawl 79 which inturn has a complementary lower coupling lug 101 at its side adjacent thepawl 78. The same coupling arrangement is provided between the pawls '79and 81, the pawl 79 having an upper coupling lug 102, and the pawl 81having a complementary lower coupling lug 103. In the assembledcondition of the indexing bar as shown in FIG. 9, the coupling lug 97over-lies the coupling lug 98; the coupling lug 99 overlies the couplinglug 101, and the coupling lug 102 overlies the coupling lug 103.

FIG. 18 shows the pawl 76 in a raised position in which its roller 86engages the notch U, of the outermost decimal ring U. The piston rod 53ofthe pneumatic cylinder 51 is shown in its retracted positioncorresponding to FIG. 3. Further, FIG. 18 shows the fence 7 bar 66 swungagainst the bar 47. The fence bar 66 has a longitudinal ledge 104 whichin the condition of the parts as shown in FIG. l8underlies a lip 106 ofthe pawl 76.

In the condition of the mechanism as shown in FIG. 3, the relationbetween the indexing pawl 76 and the ring U as illustrated by FIG.l8also exists, as shown in FIG. 9, between the pawl 77 and the ring W;between the pawl 78 and the ring X; between the pawl 79 and the ring Y;and between the pawl 81 and the ring Z. Moreover, in the condition ofthe mechanism as shown in FIGS. 3 and 9, the roller 87 of the pawl 77engages the auxiliary notch U,, of the ring U; the roller 89 of the pawl78 engages the auxiliary notch W, of the ring W; the roller 92 of thepawl 79 engages the auxiliary notch X, of the ring X, and the roller 94engages the auxiliary notch Y, of the ring Y.

Upon admission of air pressure to the barrel end of the cylinder 51(FIG. 8) the piston rod 53 advances in the direction of the arrow 107 inFIG. 18 and causes the fence bar 66 to swing away from the bar 47 intothe position illustrated by FIG. 12. During such swinging of the fencebar, the leaf 71 engages all of the pawls 76,

77, 78, 79 and 81 and forces them into a depressed condition asillustrated by FIG. 19. Continued movement of the piston rod 93 thenswings the indexing bar from the indexing position, in which it is shownin FIG. 8, to the catch position indicated by the dotted line 61 in FIG.8 and shown in FIG. 21. During such swinging of the indexing bar, therollers of all the pawls ride along the smooth bottom surfaces of thedecimal rings between the zero indexing notches and the number oneindexing notches. Upon arrival of the indexing bar in the catch positionas shown in FIGS. 20 and 21, only the pawl 76 can snap into engagementwith the indexing notch U The roller 88 (FIG. 9) of the pawl 77 isprevented from entering the indexing notch W, by contact of its roller87 with the underside of the ring U;

the roller 91 of the pawl 78 is prevented from entering the indexingnotch X, of the ring X by contact of its rol- 7 I ler 89 with the ringW; the roller 93 of the pawl 79 is prevented from entering the notch X,of the ring Y by contact of its roller 92 with the undersurface of thering X; and the roller 96 of the pawl 82 is prevented from entering-theindexing notch Z, of the ring Z by contact of its roller 94 with theundersurface of the ring Y. After theindexing arm has arrived in thecatch position illustrated by FIG. 21, air pressure is admitted to thegland end of the cylinder 51. The resulting indexing stroke of the arm64 in the direction of arrow 108 in FIG. 20 first swings the fence bar66 and lever 54 from the fall line to the dash-dotted position in FIG.20 with the result that the pawl 76 is locked in its raised position bythe ledge 104 of the fence bar 66. At the same time the ledge'l04 locksall the other pawls in their depressed positions by reason of engagementof the slanted lower sideof the ledge with the uppersides of thedepressed pawls 77, 78, 79 and 81.

Continued movement of the arm 64 in the direction of arrow 108 in FIG.20 returns the arm to its indexing position shown in FIG. 8. During suchreturn movement'ofthe indexing arm, the pawl 76, being locked in theindexing notch U, of the ring U, starts to rotate the ring U; in thedirection of arrow 108 in FIG. 22 and thereby moves the digit 1 of thering U towards its embossing position over the anvil bar 28. Uponarrival of the indexing bar in the indexing position as illustrated byFIG. 23, the digit II of the ring U has arrived in its embossingposition on the anvil bar 28. The pawl 77, however, remains depressed bycontact of its roller 87 (FIG. 9) with the underside of the ring U. Thepawls .78, 79 and-8l also remain depressed by downward anvil bar 28while the rings W, X, Y and Z remain in the zero position. Continuedback and forth movement of the indexing arm will then advance the ring Uuntil the digit 9 has arrived in the embossing position on the anvil bar28, while the rings W, X, Y and Z remain in their-zero positions.

The tenth catch stroke of the indexing bar as shown I in FIG. 24 bringsthe pawl 76 into engagement with the indexing notch U of the ring U andit also brings the auxiliary notch U, into registry with the indexingnotch W, of the ring W. Upon the subsequent tenth indexing stroke of theindexing arm 64, the cipher of the ring U and the digit 1 of the ring Wmove in unison into the embossing position on the anvil bar 28, asindicated by FIG. 25. During the next catch stroke of the indexing arm,the roller 86 of the pawl 76 engages the indexing notch U, of the ringU, but the roller 88 of the pawl 77 cannot enter the notch W of the ringW because of the contact of the roller 87 with the undersurface of thering U. Similarly, the roller 91 of the pawl 78 cannot engage theindexing notch X, of the ring X because of the contact of the roller 89with the undersurface of the ring W. Similarly, the roller 93 of thepawl 79. cannot engage the indexing notch Y, of the ring Y because ofthe contact of the roller 92 with the undersurface of the ring X; andthe roller 96 of the pawl 81 cannot engage the indexing notch Z, of thering Z because of the contact of the roller 94 with the undersurface ofthe ring Y. Consequently, the indexing arm 74 may be swung nine timesinto the catch position and back into the indexing position therebyadvancing the ring U until the digit 9 of the ring U has arrived in theembossing position on the anvil bar 28 while the digit 1 of the ring Wand the ciphers of the rings X, Y, Z remain in the embossing position.

' When the indexing arm is swung into its catch position on its 99thcatch stroke (FIG. 26), the roller 89 of the pawl 78 moves into theauxiliary notch W, of the ring W and at the same time the roller 91of'the pawl 78 moves into the indexing notch X, of the ring X. Upon the100th indexing stroke of the indexing arm, the digit 1 of the ring Xwill move into the embossing position as shown in FIG. 27 while therings U and W move into the zero position as shown in FIG. 27.

- The foregoing explanations illustrate the operating principle of theserial number embossing section. Generally speaking, the second decimalring W is advanced one digit upon every full revolution of the firstdecimal ring U; the third decimal ring X is advanced one digit uponevery full revolution of the second decimal ring W; the fourth decimalring Y is advanced one digit upon every full revolution of'the decimalring X; and the fifth decimal ring Z is advanced one digit upon everyfull revolution of the decimal ring Y.

The indexing arm 46 is pivoted on the stationary platen 2 at the centerof the decimal ring assembly UWXYZ and extends radially at'the converseside thereof. The hydraulic cylinder 51 provides power transmittingmeans for swinging the indexing arm alternately in forward and reversedirections about its pivot center. Clutch means including relativelymovable latch elements as represented by the pawls 76-81 are operativelyinterposedbetween the indexing arm and the decimal rings fortransmitting successive swinging V movements of the indexing arms insaid forward direction selectively to the decimal rings and therebypresenting the digit embossing elements of the decimal ringssuccessively in progressive serial number configurations.

In the illustrated embodiment of the invention, the latch elements 76-81of the coupling means are selectively moved into and out of clutchingengagement with the decimal rings which are operatively associated withthe latch elements and which comprise the rollers 87, 89, 92, 94 andlugs 97-103.

When the serial number configuration 09990 has been lined up on theanvil block 28 as shown in F IG. 28, the pawl 77 (FIG. 9) is keptdepressed by contact of its roller 87 with the underside of the ring U.At the same time the pawl 78 is kept depressed by downward pressure ofthe coupling lug 97 upon the-coupling lug 98; the pawl 79 is keptdepressed by downward pressure of the coupling lug 99. upon the couplinglug 101; and the pawl 81 is kept depressed by downward pressure of thecoupling lug 102 upon the coupling lug 103. Consequently, none of thealigned indexing and auxiliary notches as shown in FIG. 28 are engagedby any of the pawl rollers, except the indexing notch U, which isengaged by the roller 86 of the pawl 76.

Onthe ninth indexing stroke of the indexing arm from its catch positionshown in FIG. 28, the serial number configuration 09 999 becomes linesup on the anvil block 28 as shown in FIG. 29. In that condition theindexing notches U -Z, are aligned and the auxili-

1. A power press for continuously working strip stock into seriallynumbered plate members comprising, a stationary platen, an opposite backand forth movable platen, a flat concentric assembly of decimal ringsmounted on said stationary platen in rotatable relation to each otherand presenting an obverse side facing said movable platen; each of saiddecimal rings having a circular series of consecutive digit embossingelements at said obverse side of said ring assembly; an indexing armpivoted on said stationary platen at the center of said ring assemblyand extending radially at the converse side thereof; power transmittingmeans for swinging said indexing arm alternately in forward and reversedirections about its pivot center; clutch means including relativelymovable latch elements operatively interposed between said indexing armand said decimal rings for transmitting successive swinging movements ofsaid indexing arm in said forward direction selectively to said decimalrings and thereby presenting said digit embossing elements thereofsuccessively in progressive serial number configurations; and a counterdie on said movable platen cooperable with the obverse side of said ringassembly to emboss any serial number configuration of the latter uponstrip stock fed between said ring assembly and said counter die.
 2. Apower press as set forth in claim 1 and further comprising detent meanson said stationary platen cooperable with the converse sides,respectively, of said decimal rings so as to releasably secure thelatter in rotatively adjusted positions.
 3. A power press as set forthin claim 1 wherein said latch elements are mounted on said indexing armfor movement therewith about the center of said ring assembly; andwherein control means are operatively associated with said latchelements for selectively moving the latter into and out of clutchingengagement with said decimal rings.
 4. A power press for continuouslyworking strip stock into serially numbered plate members comprising astationary platen; an opposite back and forth movable platen; aprogressive die on said stationary platen including a perforatingsection, a serial number embossing section, an inscription embossingsection and a blanking section; and a progressive counter die on saidmovable platen adapted to mate with said progressive die on saidstationary platen; said serial number embossing section comprising aflat concentric assembly of rotatably interconnected decimal ringspresenting an obverse side facing said movable platen; each of saiddecimal rings having a circular series of consecutive digit embossinGelements at said obverse side of said ring assembly; an indexing armpivoted on said stationary platen at the center of said ring assemblyand extending radially at the converse side thereof; power transmittingmeans for swinging said indexing arm alternately in forward and reversedirections about its pivot center; clutch means including relativelymovable latch elements operatively interposed between said indexing armand said decimal rings for transmitting successive swinging movements ofsaid indexing arm in said forward direction selectively to said decimalrings and thereby presenting said digit embossing elements thereofsuccessively in progressive serial number configurations.
 5. A powerpress as set forth in claim 4 wherein said sections of said progressivedie are arranged in series so that said perforating section is succeededby said numeral embossing section; said serial number embossing sectionis succeeded by said inscription embossing section; and said inscriptionembossing section is succeeded by said blanking section.
 6. A powerpress as set forth in claim 5 wherein said inscription embossing sectionand said blanking section are separated from each other by an idlesection.
 7. A power press as set forth in claim 6 wherein said idlesection comprises a plurality of blind sections.
 8. A power press as setforth in claim 4 and further comprising circular series of anti-frictionballs operatively interposed between relatively opposite edge portionsof said decimal rings.